Gd-EOB-DTPA based magnetic resonance imaging for predicting liver response to portal vein embolization

Table 1 Magnetic resonance imaging pulse sequence protocol

	T1 (OOP) 2D FSPGR	T1 (IP) 2D FSPGR	T2 (FS)	Pre- and Post-Gd 3D FSPGR	DWI EPI (B- 0, 400, 800)
# ECHOES/SHOTS	2	2	1	1	1
TE1/TE2 (ms)	2.2-2.4	4.2-4.8	85	min	min (about 50-60)
TR/#R-R (ms)	120	120
FLIP ANGLE	85	85		15
ETL			16
FOV (cm)	48	48	48	48	48
SCAN THK (mm)	6	6	6	5-6 (-2.5)	6
FREQ × PHASE	256 × 160	256 × 160	256 × 160	256 × 128	100 × 160
NEX	1	1	4	1	1, 4, 6
PHASE FOV	0.9-1.0	0.9-1.0	0.75-1.0	0.75-1.0	0.75-1.0

Post-Gd images were obtained at late arterial phase (fluoro-triggered), 60 s, 180 s, 300 s, and 20 min post-Gd injection. Gd-EOB-DTPA was injected at 0.25 mmol/kg at 1 cc/s. TR: Repetition time; TE: Echo time; ETL: Echo train length; FS: Fat Saturated; FOV: Field of view; THK: Thickness; NEX: Number of averages; FSPGR: Fast spoiled gradient echo; DWI: Diffusion weighted imaging; EPI: Echo planar imaging; FREQ: Frequency; SEG: Segment.

Table 2 Percent in enhancement calculated between the pre-contrast phase and hepatobiliary phase of contrast administration

Average left liver	Average right liver	Average whole liver	SEG IV	SEG VIII	SEG VII	SEG V	SEG VI
118.27	129.14	123.1	137.3	118.06	129.77	146.59	122.15
106.69	124.13	114.44	96.6	112.28	129.85	129.01	125.38
131.41	132.71	132.15	122.9	126.81	139.86	121.72	142.46
133.22	130	131.79	111.85	124.87	133.4	142.06	119.66
166.19	176.9	172.31	161.17	176.29	184.49	147.19	199.65
81.83	113.24	95.79	77.14	101.13	122.32	104.6	124.92
102.63	113.57	107.5	83.77	108.26	131.64	112.28	102.11
157.2	160.56	158.88	161.62	146.42	158.69	174.57	162.57
114.15	134.94	123.39	110.28	131.55	138.96	130.07	139.16
104.98	129.04	115.68	103.53	130.94	116.86	142.72	125.66
117.83	148.94	131.66	123.38	141.55	145.57	164.26	144.37
132.54	151.34	140.9	119.4	158.55	156.5	125.41	164.92
102.2	113.12	107.06	108.72	132.15	127.38	74.83	118.13
123.9	124.27	124.07	124.09	105.84	131.57	139.36	120.32

The data are shown for segments IV, V, VI, VII, and VIII. Also the data were calculated using the average enhancement of the right liver, left liver, and whole liver.

Table 3 Summary of linear regression model results correlating enhancement and kinetic growth

Site	Estimated Slope	95% LCL	95% UCL	P value
Left liver	1.43	-2.14	5.01	0.4
Right liver	1.08	-3.24	5.4	0.6
SegIV	0.04	-3.3	3.38	0.98
SegV	1.23	-1.98	4.43	0.42
SegVI	0.35	-2.92	3.62	0.82
SegVII	1.05	-3.59	5.69	0.63
SegVIII	0.49	-3.41	4.4	0.79
Whole liver	1.37	-2.57	5.32	0.46

Linear regression assumes normality for both enhancement and kGR, it also assumes a linear relationship between the two. The estimated slope shows how much KGR increases with 1 unit increase of enhancement. P value based on test of slope against zero. If P value < 0.05 then there is significant correlation between enhancement and KGR. Conclusion: Enhancement was NOT significantly correlated with KGR in any of the site measured (all slopes not significantly different from zero, i.e., a flat line). PVE: Portal vein embolization; kGR: Kinetic growth rate; FLR: Functional liver reserve; LAVA: Liver acquisition volume acquisition; ROI: Region of interest; LCL: Lower confidence level; UCL: Upper confidence level.